code: def convert_function(function, parameters, blob_writer, opset):
      block = create_block(function, parameters, blob_writer)
  
      inputs = []
      for name, var in function.inputs.items():
          proto_type = types_to_proto(var.sym_type)
          inputs.append(pm.NamedValueType(name=name, type=proto_type))
  
      return pm.Function(
          inputs=inputs,
          opset=opset,
          block_specializations={opset: block},
      )
  
imports: import os
  import warnings
  from typing import Optional
  import numpy
  from coremltools import _OPSET, _SPECIFICATION_VERSION_IOS_15
  from coremltools import _logger
  from coremltools.converters.mil.backend.backend_helper import _get_probability_var_for_classifier
  from coremltools.converters.mil.backend.mil.helper import cast_to_framework_io_dtype, create_file_value, create_immediate_value, create_list_scalarvalue, create_scalar_value, types_to_proto
  from coremltools.converters.mil.backend.nn.load import _set_optional_inputs
  from coremltools.converters.mil.input_types import EnumeratedShapes, ImageType, RangeDim, TensorType
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Function, Program, mil_list, types
  from coremltools.converters.mil.mil.ops.registry import SSAOpRegistry
  from coremltools.converters.mil.mil.types.symbolic import any_symbolic, any_variadic, is_symbolic
  from coremltools.models.neural_network.flexible_shape_utils import NeuralNetworkImageSize, NeuralNetworkImageSizeRange, add_enumerated_image_sizes, add_multiarray_ndshape_enumeration, set_multiarray_ndshape_range, update_image_size_range
  from coremltools.models.utils import _WEIGHTS_FILE_NAME
  from coremltools.proto import FeatureTypes_pb2
  from coremltools.proto import MIL_pb2
  from coremltools.proto import Model_pb2
  from ..backend_helper import _get_colorspace_enum, _validate_image_input_output_shapes
label_desc: Use image node_id 6 for calling a global function with example usage: convert_function(function, parameters, blob_writer, opset) and returns: pm